Monthly Archives: November 2009

Hide Browser Scrollbars

Actionscript:
  1. /*
  2. This snippet is by Mels le Noble
  3. www.melslenoble.nl
  4. It will hide the browser scrollbars.
  5. */
  6.  
  7. // see if we are testing locally
  8. if (stage.loaderInfo.url.split("/")[2])
  9. {
  10.  ExternalInterface.call("function(){document.body.style.overflow='hidden';document.html.style.overflow = 'hidden';}");
  11. }

This snippet by Mels le Noble will hide the browser scrollbars. The bulk of the snippet is the javascript inside the ExternalInterface.call() method. I like the trick that Mels uses to check if the swf is local.... snippet-worthy in itself.

Posted in UI | Tagged , , , , | Leave a comment

QuickBox2D 1.1 (2 major bug fixes)

Since the release of QuickBox2D 1.0 two bugs were discovered by numerous developers. The first bug was the inability to properly destroy group objects. The second bug was a small memory leak that caused most QuickObjects to remain in memory. Both of these bugs are now resolved.

Download QuickBox2D 1.1

Testing the memory leak. In QuickBox2D 1.0 if you created and destroyed 100s of rigid bodies, the ram would very slowly rise... Sometimes it would get garbage collected, but the memory would never fully be released. I created a simple test to make sure this is fixed in 1.1:

Actionscript:
  1. import com.actionsnippet.qbox.*;
  2.  
  3. var sim:QuickBox2D = new QuickBox2D(this, {debug:false});
  4.  
  5. sim.createStageWalls();
  6.  
  7. var levelParts:Array = [];
  8. const TWO_PI:Number = Math.PI * 2;
  9.  
  10. // destroys and then creates a bunch of rigid bodies
  11. // called every second
  12. buildRandomLevel();
  13. setInterval(buildRandomLevel, 1000);
  14.  
  15. var txt:TextField = TextField(addChild(new TextField()));
  16. txt.x = txt.y = 30;
  17. txt.backgroundColor = 0xFFFFFF;
  18. sim.start();
  19.  
  20. // display amount of ram used, to make sure garbage collection is working
  21. sim.addEventListener(QuickBox2D.STEP, onStep);
  22. function onStep(evt:Event):void{
  23.     txt.text = (System.totalMemory / 100000).toFixed(2) + "mb";
  24. }
  25.  
  26. function buildRandomLevel():void{
  27.     // destroy all rigid bodies
  28.     for (var i:int = 0; i<levelParts.length; i++){
  29.         levelParts[i].destroy();
  30.     }
  31.     levelParts = [];
  32.     // create a bunch of circles and boxes
  33.     for (i = 0; i<16; i++){
  34.         var rad:Number = 0.4 ;
  35.         levelParts.push(sim.addCircle({x:1 + i * rad * 4, y : 2, radius:rad - Math.random()*0.3}));
  36.        
  37.         var rot:Number = Math.random() * TWO_PI;
  38.         levelParts.push(sim.addBox({x:4+Math.random() * i * 2, y:4+Math.random()*i,
  39.                     width:3, height:0.25, angle:rot, density:0}));
  40.     }
  41. }

This snippet creates and destroys a bunch of rigid bodies again and again.... On my macbook 2.6 Ghz intel core duo... the ram runs between 79mb and 112mb. I let it run for 40 minutes and this did not change - it always eventually returned down to 79mb.


Have a look at the swf...

Thanks to all the people who gave feedback that lead to the discover of these bugs.

Posted in Box2D, QuickBox2D, motion, pixel manipulation | Tagged , , , | 25 Comments

Paste Your Interface

Are you working on something right now that makes use of interfaces? Copy and paste an interface into the comments of this post (no need for code tags or anything)....

Actionscript:
  1. package app{
  2.    
  3.     import flash.events.IEventDispatcher;
  4.    
  5.     public interface IBaseModel extends IEventDispatcher{
  6.        
  7.         function set decimal(val:int):void;
  8.    
  9.         function get decimal():int ;
  10.        
  11.         function get stringValue():String;
  12.        
  13.         function get errorMessage():String;
  14.        
  15.         function set base(val:int):void;
  16.        
  17.         function get base():int;
  18.        
  19.         function startCounting(interval:Number, changeBy:Number):void;
  20.          
  21.         function stopCounting():void;
  22.     }
  23. }

Posted in OOP, misc | Tagged , , | 14 Comments